Prepare for support freezing bio based request queues.
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
include/linux/percpu-refcount.h | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
index 16c35a728b4c..9061c7e3113d 100644
--- a/include/linux/percpu-refcount.h
+++ b/include/linux/percpu-refcount.h
@@ -267,8 +267,9 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref)
}
/**
- * percpu_ref_tryget_live - try to increment a live percpu refcount
+ * percpu_ref_tryget_many_live - try to increment a live percpu refcount
* @ref: percpu_ref to try-get
+ * @nr: number of references to get
*
* Increment a percpu refcount unless it has already been killed. Returns
* %true on success; %false on failure.
@@ -281,7 +282,8 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref)
*
* This function is safe to call as long as @ref is between init and exit.
*/
-static inline bool percpu_ref_tryget_live(struct percpu_ref *ref)
+static inline bool percpu_ref_tryget_many_live(struct percpu_ref *ref,
+ unsigned long nr)
{
unsigned long __percpu *percpu_count;
bool ret = false;
@@ -289,10 +291,10 @@ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref)
rcu_read_lock();
if (__ref_is_percpu(ref, &percpu_count)) {
- this_cpu_inc(*percpu_count);
+ this_cpu_add(*percpu_count, nr);
ret = true;
} else if (!(ref->percpu_count_ptr & __PERCPU_REF_DEAD)) {
- ret = atomic_long_inc_not_zero(&ref->data->count);
+ ret = atomic_long_add_unless(&ref->data->count, nr, 0);
}
rcu_read_unlock();
@@ -300,6 +302,26 @@ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref)
return ret;
}
+/**
+ * percpu_ref_tryget_live - try to increment a live percpu refcount
+ * @ref: percpu_ref to try-get
+ *
+ * Increment a percpu refcount unless it has already been killed. Returns
+ * %true on success; %false on failure.
+ *
+ * Completion of percpu_ref_kill() in itself doesn't guarantee that this
+ * function will fail. For such guarantee, percpu_ref_kill_and_confirm()
+ * should be used. After the confirm_kill callback is invoked, it's
+ * guaranteed that no new reference will be given out by
+ * percpu_ref_tryget_live().
+ *
+ * This function is safe to call as long as @ref is between init and exit.
+ */
+static inline bool percpu_ref_tryget_live(struct percpu_ref *ref)
+{
+ return percpu_ref_tryget_many_live(ref, 1);
+}
+
/**
* percpu_ref_put_many - decrement a percpu refcount
* @ref: percpu_ref to put
--
2.29.2
